This proposal describes a novel strategy for the isolation of genes, mutations in which may lead to hereditary deafness. The aim of this approach is to identify and characterize the genetic loci for two X-linked ear disorders, albinism-deafness and deafness with stapes fixation. It has the following components. First, normalized cDNA libraries will be constructed which will contain nearly equal representation of high-, medium, and low-abundance messages expressed in middle and inner ear. Subtraction hybridization of ear cDNA libraries to a cDNA library from a B-lymphoblastoid cell line will yield ear-specific cDNAs. Second, previously isolated X-chromosome specific NotI-BsuE linking clones will be mapped within 10 centiMorgans of the disease loci by fluorescence in situ hybridization, and additional linking clones will be isolated by a polymerase chain reaction assisted jumping method to saturate this region. The linking clones will be used to enrich for corresponding large NotI fragments by an affinity capture method. The linking clones will also be used to isolate contigs of yeast artificial chromosome (YAC) clones. Finally, cDNAs encoded by the affinity captured DNA or by the YAC clones will be selected by a filter hybridization protocol. The selected cDNAs will be characterized to identify candidate genes responsible for albinism-deafness and deafness with stapes fixation. In addition to isolating candidate genes for these disorders, this approach will yield a repertory of ear-specific cDNAs which map to the long arm of the X-chromosome.